Concrete placing machine



April 11, 1944. c. JACKSON CONCRETE PLACING MACHINE Filed May 5, 1941 s Shets-Sheet 1 ATTORNEYS.

April 11, 1944. c; JACKSON 2,346,378

CONCRETE PLACING MACHINE Filed May 5, 1941. 3 Sheets-Sheet 2 50/201?! Jackson April 11, 1944. JACKSON} 2,346,378

CONCRETE PLACING MACHINE Filed May 5, 1941 s Sheets-She et :s

ENTOR.

ATTORNEYS.

Patented Apr. 11, 1944 CONCRETE PLACING MAGHINE Ccrwill Jackson, Ludington, Mich. Application is, 5, 1941, Serial No. 391,922

12 Claims.

This invention relates to improvements in concrete placing machines.

The main objects of this invention are:

First, to provide a machine or apparatus for the placement of concrete slabs, particularly pavements, which is of very large capacity and highly eflicient.

Second, to provide a machine of this character of the reciprocating vibrated screed type in which it is unnecessary to vibrate the screed properto such an extent or degree as to materially affect the durability or life thereof.

Third, to provide a machine or apparatus of the character described whichis highly suitable for the placement of concrete mixes having very low water content.

Fourth, to provide means for placing concrete pavements which may be effectively embodied in relatively long screeds.

Fifth, to provide a method of placing concrete of low water content and having relatively coarse aggregate which provides effective filling of the voids and a desirable surface composed mainly of the fines. r

Object relating to details and economies of the invention will appear from the description to follow. The invention is defined in the claims.

Preferred embodiments of the invention are illustrated in the accompanying drawings, in

which:

Fig. 1 is a fragmentary front perspective view of a paving machine embodying my invention, the

carriage being partially broken away and certain details omitted for convenience in illustration. l I

Fig. 2 is a fragmentary plan view of the screed and the vibratory members associated therewith.

Fig. 3 is a fragmentary front elevation.

' Fig. 4 is a fragmentary vertical section on line 4-4 of Fig. 2, the vibratory impulsein the material treated being indicated by dotted lines, the parts being shown in the position occupied when in use.

Fig. 5 is a fragmentary view of the parts in normal 'unworking position, that is, when the machine is not being'advanc'ed against a mass of concrete, and also showing a slightly modified form of vibratory member.

Fig. 6 is a fragmentary view partially in section similar to that of Fig. 5 showing another form of vibratory member. i

In the embodiment of my invention illustrated in the accompanying drawings, l represents the side forms for the concrete to be placed, these constituting rails or tracks for thepaving machine carriage 2 which is provided with flanged wheels 3. The machineis driven by a suitable engine or motonshownconventionally at 4.

The screed 5 is preferably fabricated from relatively heavy metal sections and comprises a bottom 6, a front. member or plate I, and a rear plate 8, these parts being suitably braced and reinforced; Means are commonly provided, however, for adjustment of the bottom of the screed to the desired crown of the pavement. These means are not illustrated as they form no part of this invention. It will be understood that the bottom is not rigidly fixed to the screed frame structure but is connected, as stated to .permit the crowning adjustment. The. lever 9, shown at the left of Fig. 1, is the means. for manually adjusting the crown of the screed. 3 V

The screed is supported for sliding advancement on the rails and for reciprocating movement transversely of the path of forward travel.

This transverse reciprocation is effected by the pitman ID. The driving connections for the pitman to the motor are not illustrated.

The screed is provided with wings H for retaining the mass being treated-that is, preventing its overflowing the rails as it is vibrated and also these wings serve as scrapers to clean the rails. The screed is raised and lowered from the rockshaft I2 having arms connected to the screed by the flexible connections l 3.

My Patent 2,219,246, issued October 22, 1940, discloses a reciprocated vibrated screed in which the vibrating means is mounted on the screed. Paving machines embodying this feature have been successfully used and meet certain requirements but the demand for increased speed in placement, vibration of the screed with suificient intensity to accomplish the desired results and speed, results in an undesirable short life of the screed owing to the severe vibration, and crystallization of the bolts and other parts. Further, the vibration of these very .heavy screeds is likely to settle the forms and of course this destroys the desired grade. My present invention effectively remedies these difliculties or objections that have been met and enables the effective placement of very dry concrete mixtures at .high speed and without the undesirable results noted.

I provide a plurality of vertically disposed platelike vibratory members 14 disposed vertically in end to end relation and in forwardly spaced relation to the screed. These vibratory members, in the embodiment shown in Figs. 1 to 4 inclusive, are provided with reinforcingltubular bars [5 which are welded to the bottom 'edgesthereof to pro.

against "the-same.

forcsthe vibratory member rearwardly so that thelr'es'ilientthrust member's 28 are brought into contact withthe iscreed'ias shown in Fig. 4. these ject forwardly. These bars also increase the surface of the vibratory members at this point.

The vibratory members are supported for vibratory action by means of the blade springs it which are bolted at their rear ends, as IT, to the rear portion of the screed and have goosenecks H3 at their front ends terminating in downturned arms I!) which are fixedly bolted to the tubular parts of the vibratory members at 20.

Intermediate the point of attachment to the screed and the vibratory members are the resilient or cushioning supports for the springs consisting of the clips 2| having cushioning blocks 22 of resilient material disposed above and be- I 'units23 mounted'To'n the brackets :24 on the'vibratorymembers, these'iunits comprising electric motors having rdtors 25 provided with unbalancing weights zfin "lt willbe'notedthat'the axes-'of -therotorsar'e disposed parallel'with the vibrator-y members.

In I Fig. 4 I 'indicate the concrete material tat 2l. The vibratory-unitsset up high'frequency vibrations in it'hevibratory'members and-thi assurnesan orbital path: at thebottomof the vibratory members. The vibrations are-imparted -t'o the m'ateri'ar as I' h'ave indicated by the -circular' dotted =lines.

The "vibratory members are adapted to support a substantial mass ofvthe concrete material treated :as "they iare' advanced The thrust of the material members 28 being *Jof resilient material, fabric reinforced rubber having been found quite suitlable.

These resilient'thriust members do not objecttionably dampen'the movement of the vibratory ir'ne'mbers; and this c'onhecti'onvand engagement with the screed result -1m imparting to the screed a modified vibration, thatis; modified as Zoomwall.

I The space *between: the front plate of the screed andzthe' 'vibrat'ory memberis open at the zbottomand-a the machine is advanced against -tr ieimass "of concrete indicated at 21 it-aocumu-;, 'lat'es "'or boils .up' in front 'of' the vibratory member, the vibratiorrbr action of which causes the 'concreteto' become highly workable or-semi- ;fluid. The larger portions of the aggregate are roughly struck off by the tubular portion lbof "the vibratory member :to "approximately the h'ei'ghtof the forms. Asthe machine progresses an accumulationb'f 'concretemortar or finesl'and some-small" aggregate occurswbetween the vibra- '"tory'memb'erand the 'face .of the-screed a in- 'concretedisof fluid-like consistency due to the vibratory'action of thescreedand the vibratory 'rnemr'er which constitute walls fora-relatively narrow reservoir or hopper. -Due to "the fluidlike condition the material is under hydrostatic head with reference to the bottom of the screed.

As the screed advances voids are formed between the coarse aggregate which tend to settle to the bottom of the lab on account of the vibratory action of the vibratory member. The accumulated fine concrete in the reservoir tends to flow by gravity assisted by the vibration imparted by the screed member and the vibratory member to fill voids that may exist; providing a very efiective surfacing composition. This feature of my invention is of particular value in the placement of paving slabs in which the mixture includes coarse aggregate. The result is that --it is satisfactory to place very dry concrete mixtures or mixtures having substantially no-slump water content and including coarse aggregate, as stated.

.In the embodiment shown in Figs. 5 and 6 the face plate of the screed is provided with strikeoff blades 35 disposed in :a forwardly inclined do not injure the fscreed orrcause displacement of the'forms. A stated, the resultu-i-s a machine of verylarge c-apacity.

In the embodiment shownv irnFig. 5, .the. screed 3| has the vibratory unit l 4 mounted thereom this ivibratory Y-unit having (an angle -iron.;reinforcing bari3 2 disposed with-the horizontal arm .proj'ecting rearwardly.

In the embodiment shown ineEigtfi thescreed designated. generally by theanumeral 33. has. the vibratory member [4- mounted -:-theneon,-.this vibratory member having its *lower iedgetbentrforwardlyand upwardly to provide a reinforcing bar orunem'ber 34. :Itiwill be ::,understoodthat in addition :to' the reinfiorccment, @these bars provide additional surface.

My concrete placing machine is of very-ila-rge capacity -thatwis, the-machine may be operated higher-speeds than has been "found. practical w-l th niachines embody-maths inventi n b my Patent 522-19246 in; which the .vibrating: unit is i mounted directly on thescreed; thelimitationsbf that machine being mainly in the demand=-for f larger and heavierrequipment and, as. stated; the increased.capacity or pspeed at-which the machine travels.

--Th'e* additional features bfimy present invention are of great importance.

4 I h'ave "illustrated-certain adaptations or .em-

- bodimehts-of rny invcntionandiit is: believed that these disclosures *will'ienable those 1 skilled .inthe art to embody-orladapt my improvements asmay be desired.

[Having thus -described-1mminvention; What I claim as new and 'idesire tosecure:by Letters Batent is: r

1. In a niachine of the' olass described; the "combination .of .a- .s'creed zadaptedqfior forward adi vancement -a'nd reciprocating movement vtranstory member "is advanced,-thespacebetween 'the -'front =memb er of the s creed and said vibratory member being open at-the bottomtofpermit' the smears the materiaI treated, means for vibrating said .brated at substantially less amplitude than said vibratory member at high frequency, supporting means for said vibratory member carried by said screed, and a resilient thrust memberldisposed between and engageable'by said screed and said vibratory member whereby the vibratory member is advanced and reciprocate'd as the screed'is'ad- 'vanced and reciprocated and'said screed is also vibrated.

Q 2. In a machine of the'class described, the combination of a screed adapted for forward advancement .and reciprocating movement transversely. of the path of forward trave1,a vibratory member disposed in frontof and in spaced relation to the screed and adapted to support a subjstantial mass of material treated as the vibratory member is advanced, means for vibrating said vibratory member at high frequency, supporting springs for said Vibratory member carried by said screed, and a resilient" thrust member disposed between and engageable by'said screed and said vibratory member whereby the vibratory member is advanced and 'reciprocated as the screed is advanced and reciprocated and said screed is also vibrated.

3. In a machine of the class described, the combination of a, screed, a vibratory member disposed in front of and in spaced relation to the said screed and adapted to support a substantial mass of material treated as the vibratory member is advanced, means for supporting said vibratory member on said screed permitting vibration thereof, thrust means interposed between said vibratory member and screed, and means for vibrating said vibratory member at high frequency, said thrust means engaging the vibratory member and screed to transmit vibrations from said vibratory member to said screed.

4. In a machine of the class described, the combination of a screed, a vibratory member disposed in front of and in spaced relation to said screed and adapted to support a substantial mass of material treated as the vibratory member is advanced, supporting means for said vibratory member carried by said screed, means for vibrating said vibratory member mounted thereon, and vibration transmitting means interposed between and engaging said screed and said vibratory member in thrust transmitting relation thereto whereby the vibratory member is advanced as the screed is advanced and the screed is vibrated through vibrations transmitted from said vibratory memher.

5. In a machine of the class described, the combination of a screed, a vibratory member disposed in front of and in spaced relation to the screed and adapted to support a substantial mass of material treated as the vibratory member is advanced, spring supporting means for said vibratory member carried by said screed, and resilient means between said vibratory member and screed and thrustingly engageable therewith for transmitting vibrations from said vibratory member to said screed.

6. In a machine of the class described, the

combination of a screed, a plate-like vibratory member disposed in front of said screed adapted to support a substantial mass of material treated as the screed is advanced, means for supporting said vibratory member permitting vibratory movement thereof, means for imparting high frequency vibration to said vibratory member, and means interposed between said vibratory member and said screed and thrustingly engageable therewith whereby said screed is vi- 7:;

vibratory member.

7.In a structure of the class described; the combination of a horizontally disposed platelike vibratory memberadapted to support asubstantial mass of material treated as the vibratory member is advanced, said'vibratory member having a forwardly projecting reinforcing bar secured to the lower edge thereof, a support for said vibratory member, supporting springs for said vibratory member mounted on said support, said springs being'secured to said vibratory member adjacent the upper edge thereof, means for vibrating saidvibratory member at highfrequency, and a resilient thrust member disposed between said vibratory member and itssaid support whereby when the support is advanced the vibratory member is advanced and vibratory action of the vibratory member is permitted.

8. In a machine of the class described, the combination of a screed, a vibratory member disposed in front of said screed in spaced relation and adapted to support a substantial mass of material treated as the vibratory member is advanced, supporting springs for said vibratory member permitting its vibration, means for vibrating said vibratory member at high frequency, and a resilient thrust member disposed between said screed and said vibratory member whereby the vibratory member is advanced as the screed is advanced and the screed is also vibrated, the screed being provided with a face adapted to support a substantia1 mass of the material treated.

9. In a machine of the class described, the combination of vibrated screed, provided with a face plate vibratory member disposed in front of and in spaced relation to said screed and adapted to support a substantial mass of concrete treated as the vibratory member is advanced, supporting means for said vibratory member permitting vibration thereof, and means for vibrating said vibratory member at high frequency, the width of the space between said screed and vibratory member being of the order of six inches and open at the bottom and constituting a reservoir in which fines of the concrete mixture treated accumulate in a fluid-like condition and subject to the vibrations of said screed and said vibratory member to provide a substantial head and from which reservoir they are discharged as the screed is advanced.

10. In a machine of the class described, the combination of a screed, a vibratory member disposed in front of and in spaced relation to said screed and adapted to support a substantial mass of concrete treated as the vibratory member is advanced, supporting means for said vibratory member permitting vibration thereof, means for vibrating said vibratory member at high frequency, and vibration transmitting means between said vibratory member and said screed whereby the screed is vibrated through vibrations transmitted from said vibratory member, the space between said screed and vibratory member being open at the bottom and constituting a reservoir in which fines of the concrete mixture treated accumulate in a fluidlike condition to provide a substantial head and from which they are discharged as the screed is advanced.

11. In a machine of the class described, the combination of a screed adapted to be supported by and reciprocated on forms for the material treated as the screed is advanced, said screed being provided with a face plate, a vibratory member for advancement and reciprocation with said screed and to permit high frequency vibration thereof while it is being advanced and re.- ciprocated, means for vibrating said vibratory member at high frequency, and means for transmitting modified vibrations from said vi.- bratory member to said screed, the space between the face plate .ofethe'screed and the said vibratory member constituting a narrow reservo'iropen atv the bottom, and extending substantially the length ofthe screed and in which the fines of the concrete mixture treated accumulate in a fluid-like condition'to provide a substantial head of fines for the screed surface. 12. Ina machine of the class described the combination of a vibrated screed. said screed b against the material, means for supporting said vibratory member for advancement with said Screed and to permit high frequency vibration thereof while it is being advanced and reciprocated, and means for vibrating said vibratory member at high frequency, the spacebetween the face plate of the screed and the said vibratory member constituting a narrow reservoir open at the bottom and. extending substantially the length of the screed, and in which the fines of the concrete mixture treated accumulate in a fluid-dike condition to provide a substantial head of fines for the screed surface.

CORWILL JACKSON. 

